How to Calculate Bend Allowance
When this applies
Use this guide for first-pass flat layouts before verifying against tooling-specific tables and springback studies.
Tool to use
Browser-based preliminary check for Bend Allowance Calculator — fast estimates, not code or stamped design output.
Open Bend Allowance Calculator →Steps
- 1Record material thickness, bend radius, and bend angle.
- 2Choose a k-factor or neutral-axis fraction consistent with process and material.
- 3Compute bend allowance and add to straight segments for developed length.
- 4Compare with CAD unfold and shop trial pieces when tolerance is tight.
- 5Iterate springback compensation based on empirical bends for production.
Examples
- Brake press layout for cabinet panels.
- Prototype sheet-metal bracket before laser cutting.
What to avoid
- Using generic k-factor for high-strength alloys without validation.
- Ignoring grain direction effects on cracking and springback.
- Confusing inside radius with tooling radius without offset.
Related tools
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FAQ
Air bending vs coining?
Effective radius and k-factor change; document process assumptions.
Multi-step bends?
Sequence matters; stack tolerances through the bend order.